DETERMINATION AND DIFFERENTIATION OF CHONDROCYTES

描述：（改编自研究者摘要）本申请 是基于这样的假设，即决定和分化 软骨细胞在胚胎发育过程中的生长是由一个多步骤控制的， 发育途径中，特定的转录因子发挥作用， 关键作用。 本申请建议研究两个不同的步骤 in this pathway途径. 申请人最近鉴定了一个 一种新的含有同源结构域的蛋白质，Cartl，其选择性地被 在前软骨细胞和软骨细胞中表达， 在Cartl转录本的组织分布上，Cartl发挥作用 作为软骨细胞决定途径中的转录因子 和分化，可能在早期阶段。 第一部分 建议是表征Cartl在完整小鼠中的功能， 通过产生缺乏Cartl的小鼠来研究胚胎， 转基因小鼠的转录机制，控制 Cartl基因在前软骨细胞和软骨细胞中的表达。 申请书的第二部分基于以下假设： 另一种软骨细胞特异性转录因子控制 proa 1（II）胶原蛋白基因的激活， 成熟软骨细胞的终末分化。 调查人员 建议定义COL 2A 1基因内含子1中的最小序列 其赋予B-半乳糖苷酶软骨细胞限制性表达 报告基因在转基因小鼠和胚胎中，以表征 软骨细胞特异性蛋白质结合到这个最小的功能 并克隆其cDNA。 这个应用程序是一个两- 研究途径中的两个不同步骤的方法 软骨细胞的确定和分化。

DESCRIPTION: (Adapted From Investigator's Abstract) This application is based on the hypothesis that the determination and differentiation of chondrocytes during embryonic development is controlled by a multistep developmental pathway in which specific transcription factors play a critical role. This application proposes to study two different steps in this pathway. The applicants have recently identified the DNA for a novel homeodomain containing protein, Cartl, which is selectively expressed in prechondrocytes and chondrocytes and have speculated, based on the tissue distribution of Cartl transcripts, that Cartl plays a role as a transcription factor in the pathway of chondrocytes determination and differentiation, probably at an early step. The first part of this proposal is to characterize the function of Cartl in intact mice and embryos by generating mice that are deficient in Cartl and to study in transgenic mice the transcriptional mechanisms which control the expression of the Cartl gene in prechondrocytes and chondrocytes. The second part of the application is based on the hypothesis that another chondrocyte-specific transcription factor controls the activation of the gene for proa1(II) collagen, a typical marker of terminal differentiation of mature chondrocytes. The investigators propose to define the minimal sequence in intron 1 of the COL2A1 gene which confers chondrocyte-restricted expression to a B-galactosidase reporter gene in transgenic mice and embryos, to characterize chondrocyte-specific proteins which bind to this minimal functionally active sequence and to clone their cDNAs. This application is a two- pronged approach to studying two different steps in the pathway of chondrocyte determination and differentiation.